Baffa Homebrew Projects

Baffa-2 64KB RAM

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64KB RAM for Baffa-2. The schematic is based on desing from "RC2014 64KB RAM Module" by Spencer Owen.

64KB RAM Rev.1

64KB RAM Rev.1

Related Files:


Settings

Default: starts on 4000h + page (sets start to 0h)

CP/M Setup:
  • S1 ooo
  • S2 ooo
  • S3 o= 2-3 (gnd - ignore S1 and S2)
  • S4 o= 2-3 (S3 | A15 | S6)
  • S5 =o 1-2 (!A15)
  • S6 =o 1-2 (!PAGE)
  • PAGE 1 -- CS_RAM
MSX Setup:
  • S1 ooo
  • S2 ooo
  • S3 o= 2-3 (gnd - ignore S1 and S2)
  • S4 o= 2-3 (S3 | A15 | S6)
  • S5 o= 2-3 (!A15 | S6)
  • S6 o= 2-3 (PAGE)
  • PAGE 1 -- CS_RAM
S1
=oA12 + A13 (starts on 1000h | 4KB-64KB)
o=A13 only (starts on 2000h | 8KB-64KB)
S2
=oS1 + A14 (starts on S1)
o=A14 only (starts on 4000h | 16KB-64KB)
S3
=omem conf (S1 / S2)
o=mem conf off (mem starts on 0000h)
S4 (!CS_LOW)
=oA15 + S3
o=A15 + S3 + S6
S5 (!CS_HIGH)
=o!A15 only
o=!A15 + S6
S6
=o!PAGE
o=PAGE

PAGE
pin1PAGE
pin2gnd
=page always off

Related Datasheets:


Related Projects:


Related Revisions:

  • Jul/2022 Rev.1
    * Adds Jumpers S5 and S6 to let 64KB Ram compatible with MSX1 / MSX2+

  • Nov/2021 Prototype

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